US 12,450,876 B2
Methods, systems and non-transitory computer-readable storage mediums for detecting an object of a first object type in a video sequence
Ludvig Hassbring, Lund (SE); and Song Yuan, Lund (SE)
Assigned to AXIS AB, Lund (SE)
Filed by Axis AB, Lund (SE)
Filed on Mar. 26, 2024, as Appl. No. 18/616,836.
Claims priority of application No. 23169689 (EP), filed on Apr. 25, 2023.
Prior Publication US 2024/0362893 A1, Oct. 31, 2024
Int. Cl. G06V 10/764 (2022.01); G06T 7/194 (2017.01)
CPC G06V 10/764 (2022.01) [G06T 7/194 (2017.01); G06T 2207/10016 (2013.01)] 14 Claims
OG exemplary drawing
 
1. A method for detecting objects of a first object type in a first image frame of a plurality of image frames in a video sequence capturing a scene, the method comprising:
for each image frame of the plurality of image frames:
analysing the image frame using a first algorithm to identify objects of the first object type in the image frame, the first algorithm calculating, for each area of a plurality of areas in the scene, a probability of the image data corresponding to the area being part of an object of the first object type in the image frame, the first algorithm having a probability threshold to determine whether image data is part of the object of the first object type, and storing an indicator of a difference between the probability of the image data being part of an object of the first object type and the probability threshold in a list of indicators associated with the area;
detecting objects of the first object type in the first image frame, the first image frame being a last image frame among the plurality of image frames, wherein the detecting comprises:
providing a background model of the video sequence, the background model defining, for each of the plurality of areas in the scene, whether the image data corresponding to the area in the first image frame belongs to a background or a foreground, the background model being defined by applying a second algorithm, different from the first algorithm, to at least some of the plurality of image frames; and
for each area of the scene, identifying whether the image data corresponding to the area in the first image has an uncertain object type status based on the plurality of indicators in the associated list of indicators, the list of indicators comprising a distinct indicator for each image frame of the plurality of image frames;
upon identifying that an image data has an uncertain object type status:
upon the background model defining the image data as belonging to the background in the first image, determining that the image data is not part of an object of the first object type; or
upon the background model defining the image data as belonging to the foreground in the first image, determining that the image data is part of an object of the first object type.